Maybe I'm too quilt-biased, but think of quilt as a much more
advanced

version of pkgvi and pkgdiff.

I rather like the idea of quilt, but if we intend to make quilt
part of
the standard way of developing pkgsrc, then I'd like to see quilt
itself

made less dependent on GNUisms. For example:

* it wants GNU sed, but could be converted to use BSD sed with the
"-E"

flag;
* it depends on GNU coreutils, but as far as I can see this is mostly
because it uses "cp -a" instead of the standard "cp -RPp".

* it uses GNUism in a find command (I recently fixed that with a
patch);
* it claims to require a recent version of GNU patch, but I don't
know

whether it actually uses features that are not in NetBSD's patch;
* It requires bash, but could be converted to use any POSIX shell

Indeed. That's the main (only?) complaint I have about quilt. I'd
also be happy to see its GNU-dependencies trimmed down to zero, if
possible. Don't know if I'll be able to look at this myself anytime
soon, though.